ok, after i short-circuited my PSU a few times

(do you know that they just turn on along with some of the hardware

) i now know that there isn't anything wrong with it. it says 4,94V just like it does in the bios.
but then why does Motherboard Monitor say that it only outputs 3,47V ?
and how come the dvdrom and cdwriter can't work at the same time?
do i need a stronger PSU? (400W for example) and how can i calculate how many watts my pc is using of the 300W PSU ?
and if someone could tell me some good diagnostics / overclock programs / sites i would certainly appreciate it
and tnx for the great pic bigben2k